WOUND DRESSING

Abstract

The present invention relates to a wound dressing comprising or consisting of (a) a covering layer; (b) a sheath on the wound facing side of the covering layer, (c) an absorbent core within the sheath, and (d) an adherent layer on the wound facing side of the sheath; wherein the sheath comprises (b1) an adhesive sheath layer, (b2) a proximal sheath layer on the proximal sides of the absorbent core and the adhesive sheath layer and (b3) a distal sheath layer on the distal sides of the absorbent core and the adhesive sheath layer; wherein the adherent layer comprises an opening, and wherein the adherent layer has (i) a wound facing proximal side adapted to adhere to a body part, and (ii) a distal side adhering to an outer rim of the covering layer.

Claims

1. A wound dressing comprising or consisting of (a) a covering layer; (b) a sheath on the wound facing side of the covering layer, (c) an absorbent core within the sheath, and (d) an adherent layer on the wound facing side of the sheath; wherein the sheath comprises (b1) an adhesive sheath layer, (b2) a proximal sheath layer on the proximal sides of the absorbent core and the adhesive sheath layer and (b3) a distal sheath layer on the distal sides of the absorbent core and the adhesive sheath layer; wherein the adherent layer comprises an opening, and wherein the adherent layer has (i) a wound facing proximal side adapted to adhere to a body part, and (ii) a distal side adhering to an outer rim of the covering layer.

2. Wound dressing according to claim 1, wherein the adhesive sheath layer comprises a hotmelt adhesive, preferably a hotmelt adhesive having a melting temperature of from 100° to 160° C.

3. Wound dressing according to claim 1, wherein the adhesive sheath layer is a fibrous web layer.

4. Wound dressing according to claim 1, wherein outer edges of the adhesive sheath layer, the proximal sheath layer and the distal sheath layer are connected by sealing, preferably heat-sealing, to form the sheath.

5. Wound dressing according to claim 4, wherein the sealing, preferably heat-sealing, forms a sealed edge having a width of from 0.5 cm to 3 cm, preferably from 1 cm to 1.8 cm.

6. Wound dressing according to claim 1, wherein the adhesive sheath layer is between the proximal sheath layer and the absorbent core.

7. Wound dressing according to claim 1, wherein the adherent layer comprises a first adhesive on its proximal side, wherein the first adhesive comprises preferably a silicone.

8. Wound dressing according to claim 1, wherein the adherent layer comprises a second adhesive on its distal side, wherein the second adhesive is preferably an acrylic adhesive.

9. Wound dressing according to claim 1, wherein the absorbent core is aligned with the opening.

10. Wound dressing according to claim 1, wherein the area of the opening is from 80% to 120% of the area of the absorbent core.

11. Wound dressing according to claim 1, wherein the proximal sheath layer and/or the distal sheath layer comprise or consist of a non-woven material.

12. Wound dressing according to claim 1, wherein the sheath encloses an inner sheath space that has an inner sheath area extending parallel to the adherent layer within the flat-lying and unwetted absorbent dressing; the absorbent core has an outer area extending parallel to the adherent layer within the flat-lying and unwetted absorbent dressing; and the size of the outer area of the absorbent core is from 40% to 90% of the size of the inner sheath area.

13. Wound dressing according to claim 12, wherein the outer area of the absorbent core is from 50% to 80% of the size of the inner sheath area.

14. Wound dressing according to claim 12, wherein the outer area of the absorbent core is from 1 500 mm.sup.2 to 60 000 mm.sup.2 and the inner sheath area is from 2 400 mm.sup.2 to 70 000 mm.sup.2.

15. Wound dressing according to claim 1, wherein the covering layer consists of or comprises a material selected from the group consisting of polyurethane and co-polyester.

16. Wound dressing according to claim 1, wherein the covering layer is liquid-impermeable.

17. Wound dressing according to claim 1, wherein the covering layer has a weight of from 15 to 35 g/m.sup.2, preferably 20 to 30 g/m.sup.2.

18. Wound dressing according to claim 1, wherein the covering layer has a tensile strength of from 15 to 30 N/25 mm.

19. Wound dressing according to claim 1, wherein the covering layer has an elongation of from 400% or more, preferably 500 or more.

20. Method for producing a wound dressing according to claim 1, comprising steps of heat-sealing the sheath through the covering layer.

Description

BRIEF DESCRIPTION OF FIGURES

[0062] Exemplary embodiments of the invention are shown schematically in the drawings.

[0063] FIG. 1 schematically shows a wound dressing according to the present invention, in which the adhesive sheath layer is on the proximal side of the absorbent core;

[0064] FIG. 2 shows an exploded view of the wound dressing of FIG. 1;

[0065] FIG. 3 schematically shows a top view of the wound dressing of FIG. 1;

[0066] FIG. 4 schematically shows an alternative wound dressing according to the present invention, in which the adhesive sheath layer is on the distal side of the absorbent core; and

[0067] FIG. 5 schematically shows a further alternative wound dressing according to the present invention, in which the size of the opening in the adherent layer is smaller than the size of the absorbent core.

[0068] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.

DESCRIPTION OF EMBODIMENTS

[0069] Additional advantages, characteristics, and features of the present invention will become clear from the following detailed description of exemplary embodiments with reference to the attached drawings. However, the invention is not restricted to these exemplary embodiments.

[0070] FIGS. 1 and 2 schematically show a side view and an exploded side view of a wound dressing 10 according to the present invention, in which the adhesive sheath layer 18 is on the proximal side of the absorbent core 16. The wound dressing 10 comprises a flexible, elastic PU covering layer 12, a sheath 14 and an adherent layer 23.

[0071] The sheath 14 consists—from proximal to distal direction—of a proximal sheath layer 20, adhesive sheath layer 18, absorbent core 16 and distal sheath layer 22. The proximal sheath layer 20 and the distal sheath layer 22 consist of a spunbound non-woven polypropylene. The adhesive sheath layer 18 consists of fibrous web formed by co-polyamide. The absorbent core 16 is an airlaid with superabsorbent particles and cellulose fibers having a thickness of about 1.25 mm.

[0072] The proximal sheath layer 20, adhesive sheath layer 18, absorbent core 16 and distal sheath layer 22 are aligned with each other, i.e. they share a common middle axis. The proximal sheath layer 20, adhesive sheath layer 18 and distal sheath layer 22 are substantially identical in size. The outer area 46 of the absorbent core 16 is about 64% of the size of the inner sheath area 44. The sheath 14 provides an inner sheath space 42 that has a larger volume than the unwetted absorbent core 16.

[0073] The proximal sheath layer 20, distal sheath layer 22 and adhesive sheath layer have been fused together along their outer edges 32, 34, 36 (see FIG. 2). For this purpose, the adhesive sheath layer 18 comprises a hotmelt adhesive. For fusing the layers, all layers (covering layer 12, distal sheath layer 22, absorbent core 16, adhesive sheath layer 18, proximal sheath layer 24 and adherent layer 23 have been placed on top of each other in the correct order. Subsequently, heat in the range of from 120° C. to 160° C. was applied to the outer edges 32, 34, 36 through the covering layer 12 generating a sealed edge 40.

[0074] The sheath 14 is enclosed by second sheath that is established by the covering layer 12 and the adherent layer 23 which are attached to each other. The adherent layer 23 comprises an opening 26 in its middle that is aligned with the absorbent core 16. The opening 26 is slightly larger than the absorbent core 16 in its maximal extension in a plane that is parallel to the adherent layer 23. The sheath 14 is slightly larger than the opening 26 ensuring that the absorbent core 16 is securely held inside the wound dressing 10.

[0075] The frame-shaped adherent layer 23 has an acrylic adhesive on its distal side 25 so that it adheres to an outer area of the proximal sheath layer 20 and an outer rim 30 of the covering layer. Further, the adherent layer 23 has a silicone adhesive on its proximal side 24 so that it is adapted to adhere to a body part (not shown).

[0076] FIG. 3 schematically shows a top view of the wound dressing of FIG. 1 which shows covering layer 12 in a top view. Since the covering layer 12 is transparent, the layers underneath it can also be seen. The outer rim 30 of the covering layer 12 runs around the entire circumference of the covering layer 12. Next to it, the sealed outer edge 32 of the sheath 14 can be seen. Next to this heat-sealed part of the sheath 14 and between the absorbent core 16 and the sealed outer edge 32, the free inner sheath space 42 can be seen.

[0077] FIG. 4 schematically shows an alternative wound dressing 10 according to the present invention, in which the adhesive sheath layer 18 is on the distal side of the absorbent core 16. Apart from this difference, the wound dressing 10 is essentially the same as shown in FIGS. 1 to 3.

[0078] FIG. 5 schematically shows a further alternative wound dressing 10 according to the present invention, in which the size of the opening 26 in the adherent layer is smaller than the size of the absorbent core 16. Apart from this difference, the wound dressing 10 is essentially the same as shown in FIG. 4.